Bacteria are the most abundant microorganisms on our planet, and the prevention and control of bacteria and the diseases that they cause, particularly in the agricultural field, is of utmost importance as it directly impacts the food production needed for human sustenance. Some examples of this are mentioned below.
Erwinia amylovora has caused incalculable losses by destroying complete plantations of apples and pears in the countries in which these fruits trees are cultivated. For example, in the state of Chihuahua, Mexico alone, more than 50 thousand pear trees have died and more than a million trees of different apple varieties have been infected. This has caused both large and the abandonment of the cultivation of such fruits in producing regions of that state. Thus this has evolved from a phytosanitary problem for fruit producers into a serious social problem. Fruit growers are seriously worried about the symptoms of the disease, in that the infected trees seem as if they have been burned with a flamethrower, hence the name “fire blight.” This same situation has occurred in highly industrialized countries where these fruits are cultivated, such as, for example, the United States of America, England, France, and the countries of the former Soviet Union. After blossom season, bacteria splashed by moisture events such as drizzle, dew and wind can infect succulent shoots. Blight shoot or shoot blight appears one to several weeks after falling petals. Symptoms of the disease continue to progress through the spring and summer season in susceptible tissues, such as leaves and twigs.
Pierce's disease, caused by the bacteria Xylella fastidiosa, has strategic importance due to the amount of money that it cost when it attacks crops such as vine, olive, citrus, stone fruit trees, such as plum and peach, as well as almond trees. This causes a devastating effect as a result of the large surfaces it affects. It is also one of the most studied bacteria by scientists because of the bacteria's colonizing habit, in that it can survive in different varietal cuts that have been transported without strict sanitary control at borders. The disease has spread, and has been reported already in a good number of countries in Latin America, Europe, and Asia. This disease is considered to be a main factor limiting the expansion and success of affected cultivars.
In Central America and South America, thousands of African palm trees are dying because of an illness caused by a bacterium which has not been identified correctly. This has caused a need for alternatives for its control and for a product that can counteract the devastating effects of the plague. To do so, it is necessary to establish research protocols with the appropriate scientific rigor and for those protocols to be carried out with a large team of producers, and potentially governments, in order to establish the biological cycle of the pathogen and how to treat or prevent it.
In banana producing countries threatened by a terrible disease called “moko,” caused by a bacterium named Ralstonia solanacearum, there has been the loss and abandonment of complete crops, which are impossible to replant because the pathogen survives in the soil for years on the tissues of a sick plant. Farmers have to spend large sums of money to sterilize the soil by applying toxic materials, which causes negative effects on the beneficial flora and fauna in the area, thus altering the balance and delicate nutritional biogeochemical cycles present in that ecosystem.
Having the same importance are the bacteria that attack vegetables, grasses, members of the cruciferous family, members of the solanaceae family, members of the rosaceous family, members of the ericaceous family, and the like when in favorable climatic conditions for the development of the disease you can almost completely lose the crop and to avoid it, farmers will have to invest large sums of money in applying materials based on antibiotics depending on their legislation and their availability.
The use of antibiotics in agriculture, such as gentamicin, oxytetracycline, streptomycin, and kasugamycin, offer viable alternatives for the prevention and control of these exemplary pathogens, but the use of these antibiotics has been limited during recent years in Europe, Japan, Australia, New Zealand, and Brazil. Because of this, producers have very limited options to treat or prevent the bacterial diseases which, year-by-year, reduce their crops and cause large losses of their crops. Producers can only use formulations based on copper for foliar applications, which offers a limited control of the sanitary emergency they have. In these countries, where the use of antibiotics is forbidden for agricultural use, the incidence of bacterial diseases is increasing in a worrying way, and in some places, such as Italy, Spain, New Zealand, France, and others countries, the production of both vine and kiwi are going through a delicate stage due to the presence of diseases caused by bacteria that have devastated complete cultivars. In Australia, there exists a serious worry by the government and producers of a bacterial disease that has been presenting in wheat, blueberries, sugarcane, and cereals, thereby putting in check the production of these foods. The same happens in Brazil, the United States, and England, where producers of citrus crops are reporting incalculable losses resulting from a disease called the “Yellow Dragon,” which is caused by the bacterium Candidatus liberibacter also affecting China, Taiwan, India, Malaysia, Indonesia, Myanmar, the Philippines, Pakistan, Thailand, Nepal, Saudi Arabia, Afghanistan, and others.